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Chaos radar uses messy signals to see through walls
TECHNOLOGY < Jenkins had similar success with a proof-of-principle experiment. Last year, he wired up a wheeled robot for online access and invited people to guide it through a simple maze. Over 270 people took up the challenge. He used the data they generated to build a navigation algorithm that allowed the robot to complete a maze it had not seen before. His next experiment is more ambitious. His lab has a state-ofthe-art PR2 – the same class of robot as James – that it plans to make available online. The robot will be placed in a kitchen and users will be invited to help it perform common tasks, like fetching objects from cupboards. The data they generate could help create better domestic robots, says Jenkins. The online interface will be demonstrated to researchers this August and should be available to the public by the end of the year. The initial experiments have also flagged up some potential problems. Players in the real-life Mars Escape complained that the robot had poor communication skills, for example. This may be because the real robot often prompted different behaviour to its virtual version. For example, some visitors issued commands to move a specific distance. No players in the online game issued similar instructions, so the robot had no appropriate data to draw upon. If such problems can be tackled, the technique has potential, says Jenkins. Many researchers focus on domestic tasks, but people in the outside world might prioritise other uses once they get control of robots. He draws an analogy with the early days of the internet: researchers built a data-sharing system and did not anticipate the emergence of Wikipedia and social networking. As for what those other uses are, Jenkins says we will have to wait: “If I had a good sense of other great applications, I would be doing them already.” n 16 | NewScientist | 23 July 2011
Scanner to spot the living dead A technique to spot whether fingerprints belong to a living person could prevent gruesome attacks Paul Marks
IF AN invading zombie army is staggering towards your front door, don’t worry: a fingerprintactivated door lock could save your bacon. That’s because one group of researchers has worked out how a biometric scanner can keep the undead at bay. OK, so they weren’t specifically trying to stop zombies, but there is genuine concern about dead flesh being used to spoof fingerprint scanners. Severed fingers and even fingers cut from corpses can be used to give the bad guys entry to secure facilities, to steal cars or log on to computers. It sounds outlandish, but the first reported case was in March 2005, when thieves stole a biometrics-activated Mercedes in Kuala Lumpur, Malaysia. Initially they took the owner with them so he could start the car, but they
Chaos radar uses messy signals to see through walls A NEW type of radar which harnesses chaos theory can see clearly through walls and could help find survivors in disasters. The technology could also make on-board radar a practical proposition for cars. Ultra-wideband (UWB) radar is already used to “see” through walls. It can detect the presence of people on the other side of a barrier by distortions to the reflected radio waves caused by their breathing or heartbeat. However, the radar
soon tired of his presence – and hacked off his digit before dumping him at the roadside. To combat such bloody skulduggery, researchers at Dermalog Identification Systems in Hamburg, Germany, have developed a way for a fingerprint scanner to differentiate between live and dead tissue. The trick is based on the way living tissue “blanches” – or changes colour – when blood is squeezed out of capillaries, as a fingertip is pressed against a surface, for example. Clarissa Hengfoss and her colleagues at Dermalog found that living fingers absorbed LED light at 550 nanometres on first contact and then at 1450 nanometres as the skin blanched when fully contacting the sensor (Forensic Science International, DOI: 10.1016/j. forsciint.2011.05.014). In contrast,
returns are often cluttered by interference, obscuring the signal. Now, Henry Leung and colleagues at the University of Calgary in Alberta, Canada, have found a way to sharpen the signal, which gets lost among multiple reflections within walls, known as reverberation, and by returns bouncing back via different routes. Existing UWB radars typically use a random noise signal to avoid interference between waves of the same wavelength. But because the outgoing signal is not known it takes more processing to match it to the return. A second approach is to use a wide range of sequential frequencies; this is easier to match but more prone to interference.
fingers from three cadavers showed no such change. “The spectra for light and strong contact pressure were more or less identical for fingers from dead bodies,” the Dermalog researchers say.
Leung’s team are using a “chaotic oscillator” to generate their signal. The device creates what seems like random noise, but which is actually generated by a fixed algorithm. It is matched by a receiver using the same algorithm. Because the outgoing signal is known, it is as easy to process as spread-spectrum signals. It is also irregular, like random noise, meaning reflections are less likely to interfere with each other. In tests, the chaotic signal produced better results than the other
“Vehicles could use chaos-radar sensors as part of a smart trafficmanagement system”
One Per Cent
created by imprinting copies in rubbery gels or silicone plastic, says Marcela Espinoza of the Institute of Police Science in Lausanne, Switzerland. So Espinoza is working to identify the factors that give away a fake based on the way fingerprint whorls are distorted by the different kinds of moulds used to cast them. Gel prints are made either from a direct impression of a fingerprint or by using a photo of a print to make a mould. Both methods can
scaled composites
DNA/FIGMENT/FOX / THE KOBAL COLLECTION / MOUNTAIN, PETER
For more technology stories, visit newscientist.com/technology
Rutan’s flying car
“A living finger can be distinguished from a dead one by the way it blanches when pressure is applied”
When spacecraft designer Burt Rutan takes an outlandish aviation idea seriously it’s time to sit up and take notice. The founder of Scaled Composites in Mojave, California, has designed and built his own “roadable aircraft” – a car that converts into a plane. Called the BiPod, the twin fuselage vehicle has two half-litre internal combustion engines that charge lithium-ion batteries in each nose. On the road, the BiPod’s wings are stowed and the batteries power a 15-kilowatt electric motor to drive the rear wheels. In flight, four 15-kilowatt motors power the propellers. Meanwhile, Terrafugia of Woburn, Massachusetts, has just been granted road approval for the Transition, its own roadable aircraft.
produce telltale spacings between ridges and furrows that mark the print as a counterfeit. “We are developing an algorithm that detects these forgeries,” Espinoza told New Scientist. The work both teams are doing is topical, says Tony Mansfield, a –No entry for zombies– biometrics specialist at the UK’s National Physical Laboratory in They hope their technique will London. “The International find its way into future scanners Standards Organisation is drafting to “serve as a criterion for standards for secure biometrics – authentication of a living finger”. and liveness and forgery detection Using a severed finger is not are among the anti-spoofing the only way to cheat a biometric measures. This work will probably test: fake fingerprints can be feed into their thinking.” n MARTIN BERNETTI/AFP/Getty Images
approaches. “It captures the desired properties of these two systems,” says Leung. This means the radar can see reliably through more layers. Leung’s colleagues suggest that chaos radar could be used as an on-board sensor for vehicles as part of a smart traffic-management system. As chaos signals do not interfere with each other, many could operate in the same area. Karl Woodbridge, who researches radar systems at University College London, warns that there may be some way to go before practical hardware emerges. “There are many complications in a real-world scenario which are not easy to predict in simulations.” David Hambling n
Tangled leads begone It’s a problem that frustrates every music-lover: tangled headphone leads. Apple is proposing a solution in a patent application filed last week. The folks at Infinite Loop – that’s their street in Cupertino, California – say the problem is the extreme floppiness of the wire in most headsets. Because the wire is hyperbendy, there’s nothing to prevent it looping back on itself and getting knotted. Apple’s answer is simple: stiffen lengths of the cable with extra layers of plastic between the protective sheath and the inner conductors to minimise looping. The stiffness can be varied along each lead so it is not merely rigid. Problem solved.
‘Prodcast’ tells you when to buy Ever splurged on a costly item, only to see it cheaper mere weeks later? Microsoft aims to help you dodge buyer’s remorse by predicting the best time to buy. It’s only worth holding out for a price drop if the saving is worth more to you than the time spent without the latest model, but you can’t do the calculation unless you know how much it is likely to cost in the future. Enter Prodcast, a system which looks at factors such as price history, sales volume and the time of year and then predicts for buyers when items are most likely to go on sale.
For breaking tech news go to: newscientist.com/onepercent –Radar spy for survivors– 23 July 2011 | NewScientist | 17
Scanner to spot the living dead A technique to spot whether fingerprints belong to a living person could prevent gruesome attacks Paul Marks
IF AN invading zombie army is staggering towards your front door, don’t worry: a fingerprintactivated door lock could save your bacon. That’s because one group of researchers has worked out how a biometric scanner can keep the undead at bay. OK, so they weren’t specifically trying to stop zombies, but there is genuine concern about dead flesh being used to spoof fingerprint scanners. Severed fingers and even fingers cut from corpses can be used to give the bad guys entry to secure facilities, to steal cars or log on to computers. It sounds outlandish, but the first reported case was in March 2005, when thieves stole a biometrics-activated Mercedes in Kuala Lumpur, Malaysia. Initially they took the owner with them so he could start the car, but they
Chaos radar uses messy signals to see through walls A NEW type of radar which harnesses chaos theory can see clearly through walls and could help find survivors in disasters. The technology could also make on-board radar a practical proposition for cars. Ultra-wideband (UWB) radar is already used to “see” through walls. It can detect the presence of people on the other side of a barrier by distortions to the reflected radio waves caused by their breathing or heartbeat. However, the radar
soon tired of his presence – and hacked off his digit before dumping him at the roadside. To combat such bloody skulduggery, researchers at Dermalog Identification Systems in Hamburg, Germany, have developed a way for a fingerprint scanner to differentiate between live and dead tissue. The trick is based on the way living tissue “blanches” – or changes colour – when blood is squeezed out of capillaries, as a fingertip is pressed against a surface, for example. Clarissa Hengfoss and her colleagues at Dermalog found that living fingers absorbed LED light at 550 nanometres on first contact and then at 1450 nanometres as the skin blanched when fully contacting the sensor (Forensic Science International, DOI: 10.1016/j. forsciint.2011.05.014). In contrast,
returns are often cluttered by interference, obscuring the signal. Now, Henry Leung and colleagues at the University of Calgary in Alberta, Canada, have found a way to sharpen the signal, which gets lost among multiple reflections within walls, known as reverberation, and by returns bouncing back via different routes. Existing UWB radars typically use a random noise signal to avoid interference between waves of the same wavelength. But because the outgoing signal is not known it takes more processing to match it to the return. A second approach is to use a wide range of sequential frequencies; this is easier to match but more prone to interference.
fingers from three cadavers showed no such change. “The spectra for light and strong contact pressure were more or less identical for fingers from dead bodies,” the Dermalog researchers say.
Leung’s team are using a “chaotic oscillator” to generate their signal. The device creates what seems like random noise, but which is actually generated by a fixed algorithm. It is matched by a receiver using the same algorithm. Because the outgoing signal is known, it is as easy to process as spread-spectrum signals. It is also irregular, like random noise, meaning reflections are less likely to interfere with each other. In tests, the chaotic signal produced better results than the other
“Vehicles could use chaos-radar sensors as part of a smart trafficmanagement system”
One Per Cent
created by imprinting copies in rubbery gels or silicone plastic, says Marcela Espinoza of the Institute of Police Science in Lausanne, Switzerland. So Espinoza is working to identify the factors that give away a fake based on the way fingerprint whorls are distorted by the different kinds of moulds used to cast them. Gel prints are made either from a direct impression of a fingerprint or by using a photo of a print to make a mould. Both methods can
scaled composites
DNA/FIGMENT/FOX / THE KOBAL COLLECTION / MOUNTAIN, PETER
For more technology stories, visit newscientist.com/technology
Rutan’s flying car
“A living finger can be distinguished from a dead one by the way it blanches when pressure is applied”
When spacecraft designer Burt Rutan takes an outlandish aviation idea seriously it’s time to sit up and take notice. The founder of Scaled Composites in Mojave, California, has designed and built his own “roadable aircraft” – a car that converts into a plane. Called the BiPod, the twin fuselage vehicle has two half-litre internal combustion engines that charge lithium-ion batteries in each nose. On the road, the BiPod’s wings are stowed and the batteries power a 15-kilowatt electric motor to drive the rear wheels. In flight, four 15-kilowatt motors power the propellers. Meanwhile, Terrafugia of Woburn, Massachusetts, has just been granted road approval for the Transition, its own roadable aircraft.
produce telltale spacings between ridges and furrows that mark the print as a counterfeit. “We are developing an algorithm that detects these forgeries,” Espinoza told New Scientist. The work both teams are doing is topical, says Tony Mansfield, a –No entry for zombies– biometrics specialist at the UK’s National Physical Laboratory in They hope their technique will London. “The International find its way into future scanners Standards Organisation is drafting to “serve as a criterion for standards for secure biometrics – authentication of a living finger”. and liveness and forgery detection Using a severed finger is not are among the anti-spoofing the only way to cheat a biometric measures. This work will probably test: fake fingerprints can be feed into their thinking.” n MARTIN BERNETTI/AFP/Getty Images
approaches. “It captures the desired properties of these two systems,” says Leung. This means the radar can see reliably through more layers. Leung’s colleagues suggest that chaos radar could be used as an on-board sensor for vehicles as part of a smart traffic-management system. As chaos signals do not interfere with each other, many could operate in the same area. Karl Woodbridge, who researches radar systems at University College London, warns that there may be some way to go before practical hardware emerges. “There are many complications in a real-world scenario which are not easy to predict in simulations.” David Hambling n
Tangled leads begone It’s a problem that frustrates every music-lover: tangled headphone leads. Apple is proposing a solution in a patent application filed last week. The folks at Infinite Loop – that’s their street in Cupertino, California – say the problem is the extreme floppiness of the wire in most headsets. Because the wire is hyperbendy, there’s nothing to prevent it looping back on itself and getting knotted. Apple’s answer is simple: stiffen lengths of the cable with extra layers of plastic between the protective sheath and the inner conductors to minimise looping. The stiffness can be varied along each lead so it is not merely rigid. Problem solved.
‘Prodcast’ tells you when to buy Ever splurged on a costly item, only to see it cheaper mere weeks later? Microsoft aims to help you dodge buyer’s remorse by predicting the best time to buy. It’s only worth holding out for a price drop if the saving is worth more to you than the time spent without the latest model, but you can’t do the calculation unless you know how much it is likely to cost in the future. Enter Prodcast, a system which looks at factors such as price history, sales volume and the time of year and then predicts for buyers when items are most likely to go on sale.
For breaking tech news go to: newscientist.com/onepercent –Radar spy for survivors– 23 July 2011 | NewScientist | 17